Mercury is now coming up on our left.
Named by the Greeks after the fleet-footed messenger of the gods the greyish-brown planet, moves quickly through the night sky,
Mercury is a small, rocky and heavily cratered world. The Sun’s gravity causes smaller objects from deep in space to be drawn towards the Sun. Mercury's surface resembles that of Earth's moon, scarred by many impact craters resulting from collisions with meteoroids and comets. Craters and features on Mercury are named after famous deceased artists, musicians or authors, including children's author Dr Seuss.
Mercury has no atmosphere but possesses a thin exosphere made up of atoms blasted off the surface by the solar wind and striking meteoroids. During the day, temperatures can reach 430 degrees celsius, but because the planet has no atmosphere to retain that heat, nighttime can drop to -180 degrees Celsius.
Astronomers believe it may have water ice at its north and south poles inside deep craters, where it could be cold enough to preserve water ice despite the high temperatures on sunlit parts of the planet.